Budget power supplies are usually very simplistic in the cable layout. The PowerX 550W has a little less of a traditional approach and features some cables mixed with different peripheral cables. This is nice to see as when you're building on a budget, you generally don't have a lot of peripherals and with this cable layout it is plausible that you could get away with a single peripheral cable and hide the others to keep things tidy inside the case.
The Cougar PowerX 550W features dual 12V rails. 12V1 is responsible for the Main, PCI-E and all peripheral cables, while 12V2 is responsible for nothing more than the ATX 4+4 cable. It just doesn't seem like a good idea to devote a full 22A to the auxiliary power connector, while throwing everything else on a rail that is only capable of 336W of power.
A Look Inside
There isn't too much going on inside the PowerX 550W power supply, but that's to be expected with a budget unit. There is plenty of passive cooling going and it looks like Cougar could have gone with a shorter enclosure if they really wanted to as the PCB is much shorter than the enclosure.
A single Panasonic capacitor sits on the primary side of the power supply.
Teapo capacitors litter the secondary side of the power supply.
Cougar uses their own DFT122512M 120mm fan to provide the active cooling for the PowerX 550W power supply.